When using jet flow to conduct descaling to the metal surface, as the metal plate strip has a greater width value, it is usually hard to cover the whole width when using single nozzle to conduct rust removal or descaling, so a plurality of nozzles of the same type and same geometrical fixing manner are continuously arranged in a staggered manner in the widthwise direction of the metal plate strip. Therefore, evenly distributed and steady descaling can be achieved when the metal plate strip is passing through the region covered by nozzles. While regarding to the continuous descaling production line, in order to enhance the descaling efficiency and ensure the continuous descaling, after opening each roll of metal plate strip, usually conducting fast welding between heads and tails of each roll to achieve a headless metal plate roll with infinite length so as to always ensure continuous feeding for follow-up process section. This kind of technical manner can be called as continuous descaling (or continuous metal surface processing).
This kind of continuous descaling, due to a certain difference between width specification and thickness specification of each plate roll, such as, an continuous acid-rolling line of a steel company, whose steel plate width specification of incoming materials is frequently switched between 550˜1050 mm, descaling stability of such frequently switched width value can be easily assured with respect to traditional acid pickling descaling, while it brings great influence regarding to using the jet flow physical descaling technology. This influence is mainly embodied in following aspects:
1. Established number of the nozzles must take the widest width specification as the object, and the nozzles need to be arranged are numerous.
2. When processing the plate strip of narrow specification, nozzles positioned at side portions beyond the plate width will still continue to spray, which causes great waste of electric energy and water resource.
3. The nozzles beyond the plate width are symmetrically arranged on both sides of the plate strip, they will directly spray to each other face to face when spraying; great spray force will directly cause mutual damage to both of them, which will seriously reduce the service life of the nozzle.
Based on above problems, different solving methods are specifically designed in the prior art: such as a inclined arranging manner used in Japanese patent JP55100814A, which aims to conduct integral incline to the nozzle arranged on the whole width surface based on widening or narrowing when the size specification of the plate width is switched, so as to ensure that the cleaning surface is wholly covered. However, this kind of arranging manner has very strict requirements to the strength distribution of nozzle jet flow, for the reason, after the inclined angle has changed, its former evenly distributed strength rule is broken, and the strength distribution characteristic of each nozzle is not able to strictly satisfy the even distribution of strength while jet flow of each nozzle does not interfere with each other when inclining different angles.
There is also technical solution provided by the prior art to aim at nozzle arrangement, such as conducting removal of hot rolling scale skin, cooling of continuous casting and so on by using high-pressure water, in which the nozzle arrangement mainly uses traditional straight arranging manner with respect to the largest width specification.